Vacuum pan



May 8, 1934.

A. L. WEBRE VACUUM PAN Filed July 25, 1 935 2 Sheets-Sheet l ay 8, 1934. A. L. WEBRE 1,958,07

VACUUM PAN Filed July 25. 1933 2 sheets-sheet 2 Patented May 8, 19134 Y i UNITED STATES PATENT OFFICE VACUUM PAN Alfred L. Webre, Merion, Pa., assigner to United States Pipe and Foundry Company, Burlington, N. J., a corporation of New Jersey Application July 25, 1933, Serial No. 682,061

3 Claims. (Cl. 159-25) My invention relates to the construction of vacbest understood as described in connection with uum pans such as are used for the concentration the drawings in which of sugar syrups and the object of my invention is Figure 1 is a vertical sectional elevation of a to provide an improved construction which will vacuum pan provided with my improvement. 5 insure a complete circulation of the syrup under Figure 2, a horizontal section on the line 2--2 60 treatment so that substantially all portions of the of Fig. 1, and syrup will pass to the top of the liquid column in Figure 3, a horizontal sectiony on the line 3 3 the vacuum pan and thence downward into the of Fig. 1. lower compartment of the pan and upward again A indicates the shell of the vacuum pan which through the steam belt. My invention relates to is provided With-a. hopper shaped bottom A1 from 65 that type of vacuum pans which are divided into which leads a discharge opening A2. B is a conupper and lower compartments by a steam belt duit leading through the bottom of the vacuum and provided with means for circulating the liquid chamber for the introduction of the syrup to be contents of the pan through the steam belt into concentrated. This conduit is provided with a the upper compartment, thence downward into Valve B1 and,'as shown, has its outlet opening 70 the lower compartment and my invention conlocated in a down-take conduit element, indicated sists in providing such a vacuum pan with a at G. C is avapor conduit leading from the top down-take conduit extending from the upper porof the vacuum pan and which, in apparatus of tion of the upper compartment of the pan downthis kind, is connected with a condenser not ward through the steam belt into the lower comshown. D is a steam belt which, as shown, has 75 partment and made up of a series of cylinders, the upper and lower tube sheets D1 and D2 connected lowermost one of which extends through the to the sides of the vacuum pan and to the cylinsteam belt while the upper ones, arranged in tandrical down-take element G. D3, D3, etc., are dem with this lower cylindrical element and with multiple tubes passing through the steam belt each other, are spaced apart so as to provide free and connected to the upper and lower tube sheets. 80 openings between the upper compartment of the At E, I have indicated an inlet passage for steam vacuum pan and the downtake conduit and, furand at F a drain pipe for condensate formed in ther, in providing in the separate cylindrical elethe steam belt. At F1 I have indicated an outlet ments of the down-take conduit screw propellers conduit from the steam belt which, as described of substantially equal propulsive'capacity workin my United States Patent 1,835,250, may be 85 ing in unison with each other so that each proyconnected with a vacuum pipe, f1 indicating a peller, when fed with the liq'uid syrup, will tend valve by which this conduit can be opened and to propel it downward through the subjacent porclosed. G is a downtake conduit element passing tions of the down-take conduit in equal volume through the steam belt and, as shown, forming and with equal velocity and so that the downthe inner Wall of the steam belt, connecting, as 9G take conduit will receive the syrup either through do the tubes D3, the upper and lower divisions the top of the down-take conduit or through the or chambers of the vacuum pan which I have intermediate openings formed between the sepmarked respectively as A3 and A4. G1, G2 and G3 arate cylindrical elements of the conduit in acare down-take conduit elements, cylindrical in o cordance with the level of the syrup in the vacuum shape, located in the upper chamber of the J5 pan and carry it downward into the lower com- Vacuum pan in tandem relation to the element partment of the pan with little or no inflow or G and-to each other and separated from the eleoutfiow through the open spaces in the down- -ment G and from each other by spaces indicated take conduit which lie below the space into which at H, H1 and H2. As shown, the cylindrical down- Y the syrup ows from the top of the liquid coltake elements, other than the lowermost in- 100 11m11- dicated at G, are supported in position by an By preference, I provide in the open spaces beannular system of columns. Angle irons I, as

tween the separate elements of the down-take shown, are secured at their lower ends to the conduit, vertical vanes for the purpose of countube sheet D1 and at their upper ends to the' top teracting any swirl or rotary movement which the or dome of the vacuum pan. Also secured to the 105 liquid passing through the down-take conduit may angle iron posts I are vanes extending into the be given by the screw propellers and which rospaces H, H1 and H2. The vanes extending into tative movement, if excessive, would tend to force the spaces H1 and H2 are, as shovm, bent into the syrup outward through the openings. The truncated V shape, the outer ends of the bell above and other features of my invention will be being secured to adjacent angle irons 1, all as 110 shown at J, J, J. The vanes entering the spaces H consist, as shown, of an upper series of vanes of truncated V shape, indicated at J, and a lower series of vanes J1, secured to the angle iron posts at their outer ends and to a ring K at their inner ends and this ring K serves as a support for bearing blocks indicated at K1, K2 and K3 for the shaft to be described. L is a vertical shaft extending downward centrally through the elements of the down-take conduit and supported at its top in a housing M which encloses shaft actuating gearing, not shown, driven by a motor, as indicated at N. The lower portion of this shaft L is centered by the bearing blocks K1, K2 and K3 and to this shaft are secured a series of screw propellers of approximately equal propulsive capacity, one located in each of the cylindrical elements G1, G2 and G3 of the downward conduit, as indicated at O, O1, O2 and O3.

In operation, the syrup to be concentrated is fed to the vacuum pan through the conduit B in such quantity and at such intervals as may be convenient and when the level of the syrup in the vacuum pan is at the desired height, steam is introduced into the steam belt and the shaft L set in rotation which also, of course, rotates the screwpropellers O, O1, O2 and O3 and if the level of the syrup is below the top of the down-take conduit elementY G1, the syrup will be drawn in the down-take conduit through the opening H by the action of the screw propeller O passing downward through the cylindrical element G into the lower chamber A4 of the vacuum pan and upward again through the tubes D3. When the level of the syrup is above the top of the cylindrical down-take element G1, the syrup will be drawn into this conduit by the action of the screw propeller O1 and there will be little or no inflow or outilow through the opening H, as the screw propeller O, having approximately the same propulsive capacity as the screw propeller O1, will draw the syrup across the opening H so that the circulation will be established with the fluid entering the down-take conduit through the opening H1 and with an outflow of the syrup through the annular space formed between the down-take conduit and the walls of the vacuum pan. Again, when the level of the uid extends above the opening H2, the inflow of the fluid would take place through this opening and when the level of the uid extends above the level of the element G3 the inflow will occur at the top of this element and in all cases there will be little or no inflow or outflow through the openings in the down-take conduit located below the point of entrance of the syrup to the down-take conduit and in this way I secure at all levels of the syrup in the vacuum pan a vcomplete circulation of the syrup, from a level adjacent to its top level downward ,through the conduit container into the lower compartment of the vacuum pan and upward'through the steam belt and through the annular space between the down-take conduit and the upper walls of the vacuum pan, thus insuring that the syrup, heated in passing through the steam belt, shall reach the top of the liquid down-take conduit would have to flow outwardl through the openings between the cylindrical elements of the conduit.

It will be understood that when the syrup un- I der treatment in the vacuum pan is brought to a proper consistency, it is discharged through the discharge opening A2 and a further charge:

of syrup introduced.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a vacuum pan comprising upper and lower compartments separated by a horizontal steam belt, a downtake conduit extending from the upper part of the upper compartment through the steam belt into the lower compartment, said conduit consisting of a plurality of cylindrical sections arranged in tandem and spaced from each other, in combination with. a plurality of screw propellers of similar propulsive capacity located in the individual cylindrical sections of the downtake conduit and means for simultaneously operating said screw propellers.

2. In a vacuum pan constructed as called for in claim 1, the additional constructive feature which consists in locating in the spaces separating the cylindrical elements of the down-take conduit a series of vertical vanes adapted to check rotative movement of the liquid in its passage between cylindrical elements of the downtake conduit.

3. In a Vacuum pan comprising upper and lower compartments separated by alsteam belt having upper and lower tube sheets, a multiplicity of tubes connected to the upper and lower tube sheets and a central cylindrical conduit passage connecting the upper and lower compartments of the vacuum pan, the combination therewith of a circular series of vertical columns secured to the upper tube sheet of the steam belt and to the top of the vacuum pan. a plurality of cylindrical down-take conduit sections arranged in tandem with the central conduit passage formed through the steam belt and supported on the columns in such manner as to leave open spaces between the iridividual cylinders making up the down-take conduit, vertical vanes supported by the columns and extending into the' spaces between the cylindrical elements of the down-take conduit, screw propellers located in the central passage leading through the steam belt and in the aligned cylinders making up the down-take passage and means for actuating said propellers in unison.

ALFRED L. WEBRE. 

